gre: fix netns vs proto registration ordering
GRE protocol receive hook can be called right after protocol addition is done.
If netns stuff is not yet initialized, we're going to oops in
net_generic().
This is remotely oopsable if ip_gre is compiled as module and packet
comes at unfortunate moment of module loading.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 7631b20..a2a5983 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1665,14 +1665,15 @@
printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
- if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) {
- printk(KERN_INFO "ipgre init: can't add protocol\n");
- return -EAGAIN;
- }
-
err = register_pernet_device(&ipgre_net_ops);
if (err < 0)
- goto gen_device_failed;
+ return err;
+
+ err = inet_add_protocol(&ipgre_protocol, IPPROTO_GRE);
+ if (err < 0) {
+ printk(KERN_INFO "ipgre init: can't add protocol\n");
+ goto add_proto_failed;
+ }
err = rtnl_link_register(&ipgre_link_ops);
if (err < 0)
@@ -1688,9 +1689,9 @@
tap_ops_failed:
rtnl_link_unregister(&ipgre_link_ops);
rtnl_link_failed:
- unregister_pernet_device(&ipgre_net_ops);
-gen_device_failed:
inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
+add_proto_failed:
+ unregister_pernet_device(&ipgre_net_ops);
goto out;
}
@@ -1698,9 +1699,9 @@
{
rtnl_link_unregister(&ipgre_tap_ops);
rtnl_link_unregister(&ipgre_link_ops);
- unregister_pernet_device(&ipgre_net_ops);
if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
printk(KERN_INFO "ipgre close: can't remove protocol\n");
+ unregister_pernet_device(&ipgre_net_ops);
}
module_init(ipgre_init);